U.S. patent application number 15/026346 was filed with the patent office on 2016-08-25 for refrigerator oil composition and refrigerator.
This patent application is currently assigned to JX NIPPON OIL & ENERGY CORPORATION. The applicant listed for this patent is JX NIPPON OIL & ENERGY CORPORATION. Invention is credited to Souichirou KONNO, Ken SAWADA, Akira TADA, Hitoshi TAKAHASHI.
Application Number | 20160244692 15/026346 |
Document ID | / |
Family ID | 52778708 |
Filed Date | 2016-08-25 |
United States Patent
Application |
20160244692 |
Kind Code |
A1 |
TAKAHASHI; Hitoshi ; et
al. |
August 25, 2016 |
REFRIGERATOR OIL COMPOSITION AND REFRIGERATOR
Abstract
The present invention provides a refrigerating machine oil
composition comprising an ester-based base oil, an epoxy compound,
and a carbodiimide compound, the refrigerating machine oil
composition being used with a refrigerant containing a
fluoropropene in a refrigerating machine comprising a member
containing polyethylene terephthalate and/or a member containing
hydrogenated acrylonitrile butadiene rubber.
Inventors: |
TAKAHASHI; Hitoshi; (Tokyo,
JP) ; SAWADA; Ken; (Tokyo, JP) ; TADA;
Akira; (Tokyo, JP) ; KONNO; Souichirou;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JX NIPPON OIL & ENERGY CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
JX NIPPON OIL & ENERGY
CORPORATION
Tokyo
JP
|
Family ID: |
52778708 |
Appl. No.: |
15/026346 |
Filed: |
September 30, 2014 |
PCT Filed: |
September 30, 2014 |
PCT NO: |
PCT/JP2014/076074 |
371 Date: |
March 31, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10M 133/16 20130101;
C10N 2030/36 20200501; C10N 2030/10 20130101; C10M 171/008
20130101; F25B 43/003 20130101; C09K 5/045 20130101; C10M 2207/3045
20130101; C10M 2215/086 20130101; C10M 2215/14 20130101; C10M
2207/2805 20130101; C10M 129/18 20130101; C10M 105/32 20130101;
C10N 2020/101 20200501; C10M 169/04 20130101; F25B 2500/06
20130101; C10M 2207/042 20130101; F25B 31/002 20130101; C09K
2205/126 20130101; C10N 2040/30 20130101; C10M 2207/2835
20130101 |
International
Class: |
C10M 171/00 20060101
C10M171/00; C10M 129/18 20060101 C10M129/18; F25B 31/00 20060101
F25B031/00; C10M 169/04 20060101 C10M169/04; F25B 43/00 20060101
F25B043/00; C10M 105/32 20060101 C10M105/32; C10M 133/16 20060101
C10M133/16 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 2, 2013 |
JP |
2013-207308 |
Claims
1. A refrigerating machine oil composition comprising: an
ester-based base oil; an epoxy compound; and a carbodiimide
compound, the refrigerating machine oil composition being used with
a refrigerant containing a fluoropropene in a refrigerating machine
comprising a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber.
2. The refrigerating machine oil composition according to claim 1,
wherein the ester-based base oil comprises an ester of
pentaerythritol and a monocarboxylic fatty acid and/or an ester of
dipentaerythritol and a monocarboxylic fatty acid.
3. The refrigerating machine oil composition according to claim 1,
wherein the ester-based base oil comprises an ester of
pentaerythritol and a mixture of two or more monocarboxylic fatty
acids and/or an ester of dipentaerythritol and a mixture of two or
more monocarboxylic fatty acids.
4. (canceled)
5. (canceled)
6. A refrigerating machine comprising a refrigerant circulation
system containing a compressor, a condenser, an expansion
mechanism, and an evaporator, the refrigerant circulation system
comprising a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber, and
the refrigerant circulation system being filled with a
refrigerating machine oil composition comprising an ester-based
base oil, an epoxy compound, and a carbodiimide compound and a
refrigerant containing a fluoropropene.
Description
TECHNICAL FIELD
[0001] The present invention relates to a refrigerating machine oil
composition, a working fluid composition for a refrigerating
machine, use of a composition comprising an ester-based base oil,
an epoxy compound, and a carbodiimide compound for a refrigerating
machine oil or a working fluid composition for a refrigerating
machine, use of a composition for manufacturing a refrigerating
machine oil composition or a working fluid composition for a
refrigerating machine, and a refrigerating machine.
BACKGROUND ART
[0002] In a refrigerating machine such as cold storages and air
conditioners, a refrigerating machine oil is used with a
refrigerant, in order to prevent friction, wear, and seizure in a
compression sliding portion. Examples of the properties required
for such refrigerating machine oils include compatibility with a
refrigerant and compatibility with members inside the refrigerating
machine.
[0003] That is, in addition to lubricity, thermal/chemical
stability, and refrigerant compatibility in the presence of a
refrigerant, the refrigerating machine oil is required not to
degrade the members when coming in contact with the members of a
refrigerating machine, and so on. Thus, depending on the material
of the members in the refrigerating machine, it is suggested to use
a refrigerating machine oil which is compatible with them. For
example, in the following Patent Literature 1, a refrigerating
machine oil for suppressing degradation of polyamide resin such as
nylon is disclosed.
CITATION LIST
Patent Literature
[0004] Patent Literature 1: Japanese Unexamined Patent Publication
No. 2012-131994
SUMMARY OF INVENTION
Technical Problem
[0005] However, a refrigerating machine comprises members of
various types which differ in the physical or chemical
characteristics, and it is difficult to achieve compatibility with
the members with one refrigerating machine oil.
[0006] In particular, it is extremely difficult to simultaneously
achieve compatibility with members containing polyethylene
terephthalate and compatibility with members containing
hydrogenated acrylonitrile butadiene rubber. In the case where a
conventional refrigerating machine oil is used, it is not possible
to sufficiently suppress degradation of both the members. Also, the
degree of such degradation depends on types of refrigerants, and
degradation of the above described members tends to be significant
under use of a fluoropropene refrigerant.
[0007] The present invention has been made in consideration of the
situation described above, and it is an object of the present
invention to provide a refrigerating machine oil composition and a
working fluid composition for a refrigerating machine which are
compatible with any of members containing polyethylene
terephthalate and members containing hydrogenated acrylonitrile
butadiene rubber under use of a fluoropropene refrigerant.
Solution to Problem
[0008] The present invention provides a refrigerating machine oil
composition comprising an ester-based base oil, an epoxy compound,
and a carbodiimide compound, wherein the refrigerating machine oil
composition is used with a refrigerant containing a fluoropropene
in a refrigerating machine comprising a member containing
polyethylene terephthalate and/or a member containing hydrogenated
acrylonitrile butadiene rubber.
[0009] It is preferred that the ester-based base oil comprise an
ester of pentaerythritol and a monocarboxylic fatty acid and/or an
ester of dipentaerythritol and a monocarboxylic fatty acid.
[0010] It is more preferred that the ester-based base oil comprise
an ester of pentaerythritol and a mixture of two or more
monocarboxylic fatty acids and/or an ester of dipentaerythritol and
a mixture of two or more monocarboxylic fatty acids.
[0011] Also, the present invention provides a working fluid
composition for a refrigerating machine comprising the above
described refrigerating machine oil composition and a refrigerant
containing a fluoropropene, wherein the working fluid composition
for a refrigerating machine is used in a refrigerating machine
comprising a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber.
[0012] It may also be said that the present invention is use of a
composition for a refrigerating machine oil composition or a
working fluid composition for a refrigerating machine, the
composition comprising an ester-based base oil, an epoxy compound,
and a carbodiimide compound, wherein the refrigerating machine oil
composition is used with a refrigerant containing a fluoropropene
in a refrigerating machine comprising a member containing
polyethylene terephthalate and/or a member containing hydrogenated
acrylonitrile butadiene rubber, and wherein the working fluid
composition for a refrigerating machine comprises a refrigerating
machine oil composition and a refrigerant containing a
fluoropropene and is used in a refrigerating machine comprising a
member containing polyethylene terephthalate and/or a member
containing hydrogenated acrylonitrile butadiene rubber.
[0013] It may also be said that the present invention is
application of a composition for manufacturing a refrigerating
machine oil composition or a working fluid composition for a
refrigerating machine, the composition comprising an ester-based
base oil, an epoxy compound, and a carbodiimide compound, wherein
the refrigerating machine oil composition is used with a
refrigerant containing a fluoropropene in a refrigerating machine
comprising a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber, and
wherein the working fluid composition for a refrigerating machine
comprises a refrigerating machine oil composition and a refrigerant
containing a fluoropropene and is used in a refrigerating machine
comprising a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber.
[0014] Also, the present invention provides a refrigerating machine
comprising a refrigerant circulation system containing a
compressor, a condenser, an expansion mechanism, and an evaporator,
wherein the refrigerant circulation system comprises a member
containing polyethylene terephthalate and/or a member containing
hydrogenated acrylonitrile butadiene rubber, and wherein the
refrigerant circulation system is filled with a refrigerating
machine oil composition comprising an ester-based base oil, an
epoxy compound, and a carbodiimide compound and a refrigerant
containing a fluoropropene.
Advantageous Effects of Invention
[0015] According to the present invention, it is possible to
provide a refrigerating machine oil composition and a working fluid
composition for a refrigerating machine which are compatible with
any of members containing polyethylene terephthalate and members
containing hydrogenated acrylonitrile butadiene rubber under use of
a fluoropropene refrigerant.
BRIEF DESCRIPTION OF DRAWINGS
[0016] FIG. 1 is a schematic view showing an example of the
configuration of a refrigerating machine.
DESCRIPTION OF EMBODIMENTS
[0017] Hereinafter, preferred embodiments of the present invention
will be described in detail.
[0018] A refrigerating machine oil composition according to the
present embodiment comprises an ester-based base oil, an epoxy
compound, and a carbodiimide compound, and is used with a
refrigerant containing a fluoropropene in a refrigerating machine
comprising a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber.
[0019] Also, a working fluid composition for a refrigerating
machine according to the present embodiment comprises a
refrigerating machine oil composition comprising an ester-based
base oil, an epoxy compound, and a carbodiimide compound, and a
refrigerant containing a fluoropropene, and is used in a
refrigerating machine comprising a member containing polyethylene
terephthalate and/or a member containing hydrogenated acrylonitrile
butadiene rubber. It should be noted that the working fluid
composition for a refrigerating machine according to the present
embodiment includes an aspect comprising the refrigerating machine
oil composition according to the present embodiment and a
refrigerant containing a fluoropropene.
[0020] As the ester-based base oil contained in the refrigerating
machine oil according to the present embodiment, polyol esters
obtained by the esterification reaction of a polyhydric alcohol
(polyol) and a monocarboxylic acid (monocarboxylic fatty acid),
complex esters of a polyhydric alcohol, a monocarboxylic acid, and
a polycarboxylic acid, complex esters of a polyhydric alcohol, a
monohydric alcohol, and a polycarboxylic acid, or their mixtures
are preferred.
[0021] As the above described polyhydric alcohol, neopentyl
polyols, such as neopentyl glycol, trimethylolpropane,
pentaerythritol, and dipentaerythritol are preferred. As the above
described monocarboxylic acid, monocarboxylic acids in which the
number of carbon atoms is from 4 to 10 are preferred, and specific
examples include n-butanoic acid, n-pentanoic acid, n-hexanoic
acid, n-heptanoic acid, n-octanoic acid, n-nonanic acid, n-decanoic
acid, i-butanoic acid, i-pentanoic acid, i-hexanoic acid,
i-heptanoic acid, 2-ethylpentanoic acid, 2-methylhexanoic acid,
i-octanoic acid, 2-ethylhexanoic acid, i-nonanic acid,
3,5,5-trimethylhexanoic acid, and i-decanoic acid. As the above
described polycarboxylic acid, dicarboxylic acids, such as malonic
acid, succinic acid, glutaric acid, adipic acid, pimelic acid,
suberic acid, and azelaic acid are preferred. As an alcohol and a
carboxylic acid constituting the above described ester, one alcohol
and one carboxylic acid may be used, and one or both of the alcohol
and the carboxylic acids may be used in combinations of two or
more.
[0022] As the ester-based base oil, specifically, the following
esters and the following mixtures of esters are preferably used,
for example: esters of pentaerythritol and a mixed acid of
2-methylpropanoic acid/3,5,5-trimethylhexanoic acid (at a molar
ratio of 1/9 to 9/1); esters of neopentyl glycol and a mixed acid
of 2-ethylhexanoic acid/3,5,5-trimethylhexanoic acid (at a molar
ratio of 1/9 to 9/1); esters of dipentaerythritol and a mixed acid
of 2-ethylhexanoic acid/3,5,5-trimethylhexanoic acid (at a molar
ratio of 1/9 to 9/1); esters obtained by allowing an ester
intermediate from reaction of trimethylolpropane with adipic acid
to further react with 2-ethylhexanol and distilling the remaining
unreacted material off (at a molar ratio of 5 to 40 mol % of
trimethylolpropane, 20 to 60 mol % of adipic acid, and 20 to 60 mol
% of 2-ethylhexanol); and
esters of pentaerythritol and a mixed acid of n-pentanoic
acid/n-heptanoic acid/3,5,5-trimethylhexanoic acid (at the molar
ratio of 20 to 60 mol % of n-pentanoic acid, n-heptanoic acid and 5
to 40 mol % of 3,5,5-trimethylhexanoic acid).
[0023] The refrigerating machine oil composition according to the
present embodiment may comprise a base oil other than ester-based
base oils. As the base oil, known mineral oils or synthetic oils
may be used, and it is preferred to use an ether-based base
oil.
[0024] As the ether-based base oil, various types can be used, and
typical examples include polyether compounds represented by the
following formula (1):
[Chemical Formula 1]
X O-(AO).sub.n--R.sup.1].sub.m (1)
[In the formula (1), X represents a hydrocarbon group in the form
of a monool or polyol from which a hydroxyl group is removed, A
represents an alkylene group in which the number of carbon atoms is
from 2 to 4, R.sup.1 represents a hydrogen atom or an alkyl group
in which the number of carbon atoms is from 1 to 10, in represents
the valence of X, and n represents an integer of 2 or more]. In the
formula (1), (AO).sub.n represents one formed by connecting a total
of n groups selected from one or two or more of an oxyethylene
group, an oxypropylene group, and an oxybutylene group, and it is
possible to arrange each oxyalkylene group in (AO).sub.n in a
desired order.
[0025] In the present embodiment, the content of the base oil is
preferably 20% by mass or more, and more preferably 40% by mass or
more, based on the total amount of the refrigerating machine oil
composition. The content of the ester-based base oil is preferably
20% by mass or more, and preferably 40% by mass or more, based on
the total amount of the refrigerating machine oil composition.
[0026] The refrigerating machine oil composition according to the
present embodiment comprises an epoxy compound and a carbodiimide
compound in addition to the above described base oil.
[0027] Examples of the epoxy compound include, but not particularly
limited to, glycidyl ether-type epoxy compounds, glycidyl
ester-type epoxy compounds, oxirane compounds, alkyl oxirane
compounds, alicyclic epoxy compounds, epoxidized fatty acid
monoesters, and epoxidized vegetable oils.
[0028] As the glycidyl ether-type epoxy compound, it is possible to
use, for example, an aryl glycidyl ether-type epoxy compound or
alkyl glycidyl ether-type epoxy compound represented by the
following formula (2).
##STR00001##
[In the formula (2), R.sup.2 represents an aryl group or an alkyl
group in which the number of carbon atoms is from 5 to 18].
[0029] As the glycidyl ether-type epoxy compound represented by the
formula (2), n-butylphenyl glycidyl ether, i-butylphenyl glycidyl
ether, sec-butylphenyl glycidyl ether, tert-butylphenyl glycidyl
ether, pentylphenyl glycidyl ether, hexylphenyl glycidyl ether,
heptylphenyl glycidyl ether, octylphenyl glycidyl ether,
nonylphenyl glycidyl ether, decylphenyl glycidyl ether,
decylglycidyl ether, undecylglycidyl ether, dodecyl glycidyl ether,
tridecyl glycidyl ether, tetradecyl glycidyl ether, and
2-ethylhexyl glycidyl ether are preferred.
[0030] If the number of carbon atoms of the alkyl group represented
by R.sup.2 is 5 or more, the stability of the epoxy compound is
ensured, and it is possible to suppress decomposition before
reaction with moisture, fatty acid, and oxidization deteriorated
material or self-polymerization between epoxy compounds, and the
intended function becomes easy to achieve. Meanwhile, if the number
of carbon atoms of the alkyl group represented by R.sup.2 is 18 or
less, the solubility in a refrigerant, in particular, a
hydrofluorocarbon refrigerant is well maintained, and it is
possible to make malfunctions such as cooling defects due to
deposition in refrigerating apparatuses less likely to occur.
[0031] Also, as the glycidyl ether-type epoxy compound, other than
epoxy compounds represented by the formula (2), it is possible to
use neopentyl glycol diglycidyl ether, trimethylolpropane
triglycidyl ether, pentaerythritol tetraglycidyl ether,
1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether,
polyalkylene glycol monoglycidyl ethers, polyalkylene glycol
diglycidyl ethers and the like.
[0032] As the glycidyl ester-type epoxy compound, it is possible to
use, for example, those represented by the following formula
(3).
##STR00002##
[In the formula (3), R.sup.3 represents an aryl group, an alkyl
group in which the number of carbon atoms is from 5 to 18, or an
alkenyl group].
[0033] As the glycidyl ester-type epoxy compound represented by the
formula (3), glycidyl benzoate, glycidyl neodecanoate,
glycidyl-2,2-dimethyloctanoate, glycidyl acrylate, and glycidyl
methacrylate are preferred.
[0034] If the number of carbon atoms of the alkyl group represented
by R.sup.3 is 5 or more, the stability of the epoxy compound is
ensured, and it is possible to suppress decomposition before
reaction with moisture, fatty acid, and oxidization deteriorated
material or self-polymerization between epoxy compounds, and the
intended function becomes easy to achieve. Meanwhile, if the number
of carbon atoms of the alkyl group or alkenyl group represented by
R.sup.3 is 18 or less, the solubility in a refrigerant, in
particular, a hydrofluorocarbon refrigerant is well maintained, and
it is possible to make malfunctions such as cooling defects due to
deposition in refrigerating apparatuses less likely to occur.
[0035] An alicyclic epoxy compound is a compound having a partial
structure represented by the following formula (4) in which carbon
atoms constituting the epoxy group directly constitute the
alicyclic ring.
##STR00003##
[0036] As the alicyclic epoxy compound, 1,2-epoxycyclohexane,
1,2-epoxycyclopentane,
3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate,
bis(3,4-epoxycyclohexylmethyl)adipate, exo-2,3-epoxynorbornane,
bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate,
2-(7-oxabicyclo[4.1.0]hept-3-yl)-spiro(1,3-dioxane-5,3'-[7]oxabicyclo[4
0.1.0]heptane,
4-(1'-methylepoxyethyl)-1,2-epoxy-2-methylcyclohexane, and
4-epoxyethyl-1,2-epoxycyclohexane are preferred.
[0037] Examples of the allyloxirane compound include
1,2-epoxystyrene and alkyl-1,2-epoxystyrenes.
[0038] Examples of the alkyl oxirane compound include
1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane,
1,2-epoxyheptane, 1,2-epoxyoctane, 1,2-epoxynonane,
1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane,
1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane,
1,2-epoxyhexadecane, 1,2-epoxyheptadecane, 1,2-epoxyoctadecane,
1,2-epoxynonadecane, and 1,2-epoxyicosane.
[0039] Examples of the epoxidized fatty acid monoester include
esters of an epoxidized fatty acid in which the number of carbon
atoms is from 12 to 20 and an alcohol in which the number of carbon
atoms is from 1 to 8 or a phenol or alkyl phenol. As the epoxidized
fatty acid monoester, butyl, hexyl, benzyl, cyclohexyl,
methoxyethyl, octyl, phenyl, and butylphenyl esters of epoxystearic
acids are preferably used.
[0040] Examples of the epoxidized vegetable oil include epoxy
compounds of vegetable oils, such as soy oil, linseed oil, and
cottonseed oil.
[0041] The content of the epoxy compound is preferably 0.1% by mass
or more and 4.5% by mass or less, more preferably 0.5% by mass or
more and 3.5% by mass or less, further preferably 1.0% by mass or
more and 2.5% by mass or less, based on the total amount of the
refrigerating machine oil composition. If the content is the above
described lower limit or more, it is possible to suppress an
increase in the acid value of the refrigerating machine oil
composition. If the content is the above described upper limit or
less, even in the case where the refrigerating machine oil
composition is used with a fluoropropene refrigerant, it is
possible to suppress a deterioration in a member containing
polyethylene terephthalate and a member containing hydrogenated
acrylonitrile butadiene rubber.
[0042] As the carbodiimide compound, which is not particularly
limited, for example, it is possible to use dialkylcarbodiimide,
diphenylcarbodiimide, and bis(alkylphenyl)carbodiimide.
[0043] Example of the dialkylcarbodiimide include
diisopropylcarbodiimide and dicyclohexylcarbodiimide.
[0044] Examples of the bis(alkylphenyl)carbodiimide include
ditolylcarbodiimide, bis(isopropylphenyl)carbodiimide,
bis(diisopropylphenyl)carbodiimide,
bis(triisopropylphenyl)carbodiimide, bis(butylphenyl)carbodiimide,
bis(dibutylphenyl)carbodiimide, and
bis(nonylphenyl)carbodiimide.
[0045] The content of the carbodiimide compound is preferably 0.01%
by mass or more and 1% by mass or less, more preferably 0.05% by
mass or more and 0.5% by mass or less, based on the total amount of
the refrigerating machine oil composition. If the content is the
above described lower limit or more, the stability of the
refrigerating machine oil composition is more increased. If the
content is the above described upper limit or less, it is possible
to suppress occurrence of sludge derived from additives during a
long time of use.
[0046] The kinematic viscosity of the refrigerating machine oil
composition at 40.degree. C. can be preferably from 3 to 1000
mm.sup.2/s, more preferably from 4 to 500 mm.sup.2/s, and further
preferably from 5 to 400 mm.sup.2/s. The kinematic viscosity of the
refrigerating machine oil composition at 100.degree. C. can be
preferably from 1 to 100 mm.sup.2/s and more preferably from 2 to
50 mm.sup.2/s. The kinematic viscosity in the present invention
means the kinematic viscosity measured in compliance with JIS
K2283:2000.
[0047] The pour point of the refrigerating machine oil composition
can be preferably -10.degree. C. or less and more preferably
-20.degree. C. or less. The pour point in the present invention
means the pour point measured in compliance with JIS
K2269-1987.
[0048] The volume resistivity of the refrigerating machine oil
composition can be preferably 1.0.times.10.sup.9 .OMEGA.m or more,
more preferably 1.0.times.10.sup.10 .OMEGA.m or more, and further
preferably 1.0.times.10.sup.11 .OMEGA.m or more. In particular, in
the case of being used for a hermetic-type refrigerating machine,
it is preferred that the composition be highly insulating. The
volume resistivity in the present invention means the volume
resistivity at 25.degree. C. measured in compliance with JIS
C2101:1999.
[0049] The moisture content of the refrigerating machine oil
composition can be preferably 200 ppm or less, more preferably 100
ppm or less, and further preferably 50 ppm or less, based on the
total amount of the refrigerating machine oil composition.
Particularly, in the case of being used for a hermetic-type
refrigerating machine, it is preferred that the moisture content be
low, from the viewpoint of the influence on the thermal/chemical
stability and the electrical insulation property of the
refrigerating machine oil composition.
[0050] The acid value of the refrigerating machine oil composition
can be preferably 10.0 mgKOH/g or less, more preferably 1.0 mgKOH/g
or less, and further preferably 0.1 mgKOH/g or less. The hydroxy
value of refrigerating machine oil composition can be preferably
50.0 mgKOH/g or less, more preferably 30.0 mgKOH/g or less, and
further preferably 10.0 mgKOH/g or less. It is preferred that the
acid value and the hydroxy value of the refrigerating machine oil
be in the above described range, from the viewpoints of prevention
of corrosion of the metal used in a refrigerating machine or piping
and of prevention of degradation of the ester contained in the
refrigerating machine oil composition. The acid value in the
present invention means the acid value measured in compliance with
JIS K2501:2003. The hydroxy value in the present invention means
the hydroxy value measured in compliance with JIS K0070-1992.
[0051] The ash content of the refrigerating machine oil composition
can be preferably 100 ppm or less and more preferably 50 ppm or
less, from the viewpoint of increasing the thermal/chemical
stability of the refrigerating machine oil composition and
suppressing the occurrence of sludge and the like. The ash content
in the present invention means the ash content measured in
compliance with JIS K2272: 1998.
[0052] In the present embodiment, in order to impart total
performance, it is possible to add the following additives or other
known additives to the refrigerating machine oil composition as
appropriate, within the extent that the properties of the
refrigerating machine oil composition are not impaired.
Antiwear agent: sulfur-based, phosphorous-based, zinc
thiophosphate-based, and the like; Antioxidant: phenol-based,
amine-based, phosphorous-based, and the like; Metal deactivator:
benzotriazole (derivatives), thiadiazoles, dithiocarbamates, and
the like; Oiliness agent: higher fatty acids, alcohols, amines, and
the like; and Antifoaming agent: silicone oils and the like.
[0053] The refrigerating machine oil composition according to the
present embodiment is used with a refrigerant containing a
fluoropropene, and also, the working fluid composition for a
refrigerating machine according to the present embodiment comprises
a refrigerant containing a fluoropropene.
[0054] As the fluoropropene refrigerant, fluoropropenes of which
the number of fluorine atoms is 3 to 5 are preferred, and it is
preferred that the fluoropropene refrigerant be any one of
1,2,3,3,3-pentafluoropropene (HFO-1225ye),
1,3,3,3-tetrafluoropropene (HFO-1234ze), 2,3,3,3-tetrafluoropropene
(HFO-1234yf), 1,2,3,3-tetrafluoropropene (HFO-1234ye), and
3,3,3-trifluoropropene (HFO-1243zf) or a mixture of two or more of
these. From the viewpoint of refrigerant physical properties, it is
preferred that the refrigerant be one or two or more selected from
HFO-1225ye, HFO-1234ze, and HFO-1234yf.
[0055] The refrigerant used with the refrigerating machine oil
composition according to the present embodiment may include
refrigerants other than fluoropropene. Examples of the refrigerant
other than fluoropropene include saturated hydrofluorocarbon
refrigerant, fluorine-containing ether-based refrigerants such as
perfluoroether, bis(trifluoromethyl)sulfide refrigerants,
trifluoroiodomethane refrigerants, and natural refrigerant, such as
dimethyl ether, carbon dioxide, ammonia, and hydrocarbons.
[0056] The refrigerating machine oil composition and the working
fluid composition for a refrigerating machine according to the
present embodiment are preferably used for a refrigerating machine
comprising a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber.
Specific examples of the refrigerating machine include a
refrigerating machine, such as automobile air conditioners
comprising a reciprocating or rotary compressor, air conditioners,
dehumidifiers, cold storages, freezers, freezing cold storages,
vending machines, showcases, and cooling apparatus for chemical
plants.
[0057] Hereinafter, the aforementioned refrigerating machine will
be described in more detail. FIG. 1 is a schematic view showing an
example of the configuration of a refrigerating machine. As shown
in FIG. 1, a refrigerating machine 10 comprises a refrigerant
circulation system in which at least a compressor 1, a condenser 2,
an expansion mechanism 4, and an evaporator 5 are successively
connected by a passage 6. The refrigerant circulation system may
further comprise a desiccator 3. Also, the refrigerant circulation
system a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber.
[0058] In the compressor 1, a small amount of the refrigerant and a
large amount of the refrigerating machine oil composition coexist
under a high temperature (usually 70 to 120.degree. C.) condition.
The refrigerant released from the refrigerant compressor 1 to the
passage 6 is gaseous and contains a small amount of (usually 1 to
10% of) the refrigerating machine oil composition as mist, and in
this mist refrigerating machine oil composition, a small amount of
the refrigerant is dissolved (point a in FIG. 1). Next, in the
condenser 2, the gaseous refrigerant is compressed to be
high-density fluid, and under a relatively high temperature
(usually 50 to around 70.degree. C.) condition, a large amount of
the refrigerant and a small amount of the refrigerating machine oil
coexist (point b in FIG. 1). Furthermore, the mixture of a large
amount of the refrigerant and a small amount of the refrigerating
machine oil is successively supplied to the desiccator 3, the
expansion mechanism 4, and the evaporator 5 to rapidly have a lower
temperature (usually -40 to 0.degree. C.) (points c and d in FIG.
1) and be returned back to the refrigerant compressor 1.
[0059] As the compressor 1, it is possible to use both open type
compressors, which have a prime mover externally, and hermetic type
compressors, which incorporate a motor internally.
[0060] Examples of the open type compressor include reciprocating
types such as piston/crank types and piston/swash plate types, and
rotating types such as rotating piston types, rotary vane types,
scroll types, and screw types. Examples of the external prime
movers include engines and motors, but particularly in the case of
automobile air conditioners, it is common to use driving engines as
external prime movers.
[0061] Examples of the hermetic type compressor include
high-pressure container-type compressors housing a motor comprising
a rotor and a stator in a sealed container storing a refrigerating
machine oil composition, a rotation axis fitted in the rotor, and a
compressor linked to the motor via the rotation axis, wherein
high-pressure refrigerant gas released from the compressor is
retained in the sealed container, and low-pressure container-type
compressors housing a motor comprising a rotor and a stator in a
sealed container storing a refrigerating machine oil composition, a
rotation axis fitted in the rotor, and a compressor linked to the
motor via the rotation axis, wherein high-pressure refrigerant gas
released from the compressor is directly discharged out of the
sealed container.
[0062] The desiccator 3 is packed with a desiccant such as
synthetic zeolites comprising, for example, silicic acid and alkali
aluminate metal complex salts.
[0063] In the refrigerant circulation system of the refrigerating
machine 10, a member containing polyethylene terephthalate and/or a
member containing hydrogenated acrylonitrile butadiene rubber are
used in, for example, insulating portions inside the compressor 1
and sealing materials for preventing leakage of the refrigerant and
the refrigerating machine oil composition in the compressor 1.
Examples
[0064] Hereinafter, the present invention will be described based
on Examples and Comparative examples, but the present invention is
not limited to the Examples.
[0065] In Examples 1 to 16, Comparative Examples 1 to 10, and
Reference Examples 1 to 2, the following base oils and additives
were used to prepare refrigerating machine oil compositions of
which compositions are shown in Tables 1 to 5, and the following
material compatibility test was conducted on each refrigerating
machine oil composition obtained. The results are shown in Tables 1
to 5.
[0066] (Base Oil)
Base oil 1: an ester base oil in which (a1) an ester of
pentaerythritol and a mixed acid of 2-methylpropanic
acid/3,5,5-trimethylhexanoic acid (at a molar ratio of 1/1) and
(31) an ester of neopentyl glycol and a mixed acid of
2-ethylhexanoic acid/3,5,5-trimethylhexanoic acid (at a molar ratio
of 1/1) are mixed at a ratio of (a1) 50% by mass: (b1) 50% by mass.
Base oil 2: an ester base oil in which (a2) an ester of
pentaerythritol and a mixed acid of 2-ethylhexanoic
acid/3,5,5-trimethylhexanoic acid (at a molar ratio of 1/1) and
(b2) an ester of dipentaerythritol and a mixed acid of
2-ethylhexanoic acid/3,5,5-trimethylhexanoic acid (at a molar ratio
of 1/1) are mixed at a ratio of (a2) 75% by mass:(b2) 25% by mass.
Base oil 3: an ester base oil obtained by reacting 2-ethylhexanol
(2.0 mol) with an ester intermediate of trimethylolpropane (1 mol)
and adipic acid (2.4 mol) and distilling the remaining unreacted
material off. Base oil 4: an ester base oil of pentaerythritol and
a mixed acid of n-pentanoic acid/n-heptanoic
acid/3,5,5-trimethylhexanoic acid (at a molar ratio of
40/40/20).
[0067] (Additives)
(A) Epoxy Compounds
[0068] A1: glycidyl neodecanoate A2: 2-ethylhexyl glycidyl ether
A3: 1,2-epoxytetradecane A4:
3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate
(CELLOXIDE 2021P)
(B) Carbodiimide Compounds
[0069] B1: bis(diisopropylphenyl)carbodiimide B2:
diisopropylcarbodiimide
[0070] (Material Compatibility Test)
[0071] A sample of a strip made of hydrogenated acrylonitrile
butadiene rubber (H-NBR) or polyethylene terephthalate (PET) placed
in a mixture of 80 g of a refrigerating machine oil composition and
20 g of 2,3,3,3-tetrafluoropropene refrigerant (HFO-1234yf) of
which moisture content was adjusted to 500 ppm was heated in a 200
ml autoclave at 150.degree. C. for 200 hours. After heating was
finished, the acid value of the refrigerating machine oil
composition was measured, the tensile strength of the strips made
of H-NBR or PET was measured, and the tensile strength change ratio
(%) defined by the following formula was calculated.
Tensile strength change ratio [%]=(Tensile strength of the strip
after the test/Tensile strength of the strip before the
test).times.100
[0072] The strips made of H-NBR and PET used in the test were each
shaped into the following form.
H-NBR: length.times.width.times.thickness=5 cm.times.2 cm.times.0.2
cm
PET: length.times.width.times.thickness=5 cm.times.2 cm.times.300
.mu.m
The acid value was measured in compliance with JIS K2501 "Petroleum
products and lubricants--Determination of neutralization number",
and the tensile strength was measured in compliance with JIS
K6251.
TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4
Example 5 Example 6 Composition Base oil Base oil 1 Balance Balance
Balance Balance Balance Balance (% by mass) Base oil 2 -- -- -- --
-- -- Base oil 3 -- -- -- -- -- -- Base oil 4 -- -- -- -- -- --
Additive A1 4.5 2.0 0.5 0.1 0.1 0.1 A2 -- -- -- -- -- -- A3 -- --
-- -- -- -- A4 -- -- -- -- -- -- B1 0.01 0.1 0.1 3.0 1.0 0.1 B2 --
-- -- -- -- -- Test refrigerant HFO- HFO- HFO- HFO- HFO- HFO-
1234yf 1234yf 1234yf 1234yf 1234yf 1234yf Material H-NBR Tensile 82
88 86 86 90 89 compatibility strength change ratio (%) Acid value
0.04 0.06 0.09 0.09 0.13 0.19 (mgKOH/g) PET Tensile 83 83 88 84 85
87 strength change ratio (%) Acid value 0.01 0.01 0.02 0.02 0.03
0.04 (mgKOH/g)
TABLE-US-00002 TABLE 2 Example 7 Example 8 Example 9 Example 10
Example 11 Example 12 Composition Base oil Base oil 1 -- -- -- --
-- -- (% by mass) Base oil 2 Balance Balance Balance Balance
Balance Balance Base oil 3 -- -- -- -- -- -- Base oil 4 -- -- -- --
-- -- Additive A1 -- -- -- -- -- -- A2 4.5 2.0 0.5 0.1 0.1 0.1 A3
-- -- -- -- -- -- A4 -- -- -- -- -- -- B1 0.01 0.1 0.1 3.0 1.0 0.1
B2 -- -- -- -- -- -- Test refrigerant HFO- HFO- HFO- HFO- HFO- HFO-
1234yf 1234yf 1234yf 1234yf 1234yf 1234yf Material H-NBR Tensile 82
87 85 85 89 89 compatibility strength change ratio (%) Acid value
0.05 0.07 0.09 0.09 0.12 0.18 (mgKOH/g) PET Tensile 81 85 88 83 85
86 strength change ratio (%) Acid value 0.01 0.01 0.03 0.03 0.05
0.06 (mgKOH/g)
TABLE-US-00003 TABLE 3 Example 13 Example 14 Example 15 Example 16
Composition Base oil Base oil 1 -- -- -- -- (% by mass) Base oil 2
-- -- -- -- Base oil 3 Balance Balance -- -- Base oil 4 -- --
Balance Balance Additive A1 -- -- -- -- A2 -- -- -- -- A3 4.5 0.1
-- -- A4 -- -- 4.5 0.1 B1 0.01 1.0 -- -- B2 -- -- 0.01 1.0 Test
refrigerant HFO- HFO- HFO- HFO- 1234yf 1234yf 1234yf 1234yf
Material H-NBR Tensile strength 87 82 85 86 compatibility change
ratio (%) Acid value 0.09 0.15 0.08 0.16 (mgKOH/g) PET Tensile
strength 83 83 85 83 change ratio (%) Acid value 0.03 0.07 0.05
0.09 mgKOH/g)
TABLE-US-00004 TABLE 4 Comp. Comp. Comp. Comp. Comp. Ref. Example 1
Example 2 Example 3 Example 4 Example 5 Example 1 Composition Base
oil Base oil 1 Balance Balance Balance Balance Balance Balance (%
by mass) Base oil 2 -- -- -- -- -- -- Base oil 3 -- -- -- -- -- --
Base oil 4 -- -- -- -- -- -- Additive A1 5.0 2.0 0.5 0.1 -- 0.1 A2
-- -- -- -- -- -- A3 -- -- -- -- -- -- A4 -- -- -- -- -- -- B1 --
-- -- -- 0.1 -- B2 -- -- -- -- -- -- Test refrigerant HFO- HFO-
HFO- HFO- HFO- R410A 1234yf 1234yf 1234yf 1234yf 1234yf Material
H-NBR Tensile 72 87 83 87 92 86 compatibility strength change ratio
(%) Acid value 0.05 0.29 0.48 1.32 0.77 0.17 (mgKOH/g) PET Tensile
69 81 82 85 87 82 strength change ratio (%) Acid value 0.01 0.17
0.34 0.89 0.43 0.05 (mgKOH/g)
TABLE-US-00005 TABLE 5 Comp. Comp. Comp. Comp. Comp. Ref. Example 6
Example 7 Example 8 Example 9 Example 10 Example 2 Composition Base
oil Base oil 1 -- -- -- -- -- -- (% by mass) Base oil 2 Balance
Balance Balance Balance Balance Balance Base oil 3 -- -- -- -- --
-- Base oil 4 -- -- -- -- -- -- Additive A1 -- -- -- -- -- -- A2
5.0 2.0 0.5 0.1 -- 0.1 A3 -- -- -- -- -- -- A4 -- -- -- -- -- -- B1
-- -- -- -- 0.1 -- B2 -- -- -- -- -- -- Test refrigerant HFO- HFO-
HFO- HFO- HFO- R410A 1234yf 1234yf 1234yf 1234yf 1234yf Material
H-NBR Tensile 74 88 82 86 91 85 compatibility strength change ratio
(%) Acid value 0.06 0.25 0.47 1.37 0.79 0.18 (mgKOH/g) PET Tensile
70 82 85 89 86 85 strength change ratio (%) Acid value 0.01 0.15
0.35 0.88 0.45 0.06 (mgKOH/g)
REFERENCE SIGNS LIST
[0073] 1 . . . compressor, 2 . . . condenser, 3 . . . desiccator, 4
. . . expansion mechanism, 5 . . . evaporator, 6 . . . passage, 10
. . . refrigerating machine.
* * * * *